In the past, electrical connectors have been widely used in order to connect printed circuit boards, hereafter referred to as "PCB's", to each other. Such electrical connectors as disclosed in U.S. Pat. No. 5,224,866 are equipped with a plug connector and a cap connector that are mounted on different boards and are connected to each other. The PCB's are connected to each other by connecting the plug connector and cap connector. The plug connector and cap connector each have a plurality of contacts and a housing in which these contacts are lined up at a given pitch. Ordinarily, the contacts lined up in the housing of the plug connector possess spring forces, so that when the plug connector and cap connector are connected, the contacts lined up in the respective housings are caused to contact each other with a given force as a result of these spring forces, thus establishing an electrical connection.
As a result of the miniaturization of electrical connectors in recent years, there has been a tendency for the contacts to become smaller and for the pitch at which the contacts are lined up to become narrower. Furthermore, there has also been a tendency for the contacts to become shorter, in order to reduce the distance between the connected boards when the boards are connected face-to-face by such an electrical connector. In cases where the contacts are thus made smaller and shorter, the spring forces of the contacts drops so that there is a drop in the contact pressure between the contacts, thus leading to the danger of an inadequate electrical connection.
U.S. Pat. No. 5,224,866 discloses an electrical connector assembly for electrical connection to conductive pads on board members including plug and receptacle connectors. Each connector has electrical terminals secured in a housing, the terminals including contact sections and termination sections for electrical connection to the conductive pads on one of the board members. The terminals in the receptacle or cap connector have a linear configuration secured in the housing and include contact sections for electrically connecting with the contact sections of the plug connector when the plug connector and receptacle connector are mated together.
The object of the present invention is to provide an electrical connector that makes it possible to cause the respective terminals or contacts to electrically and mechanically engage each other with a high contact pressure even if the contacts are made smaller or shorter.
The electrical connector of the present invention, which is used in order to achieve the above mentioned object, is an electrical connector that is equipped with a plug connector and a cap connector in which the plug of first contacts and the cap or second contacts that contact each other are respectively aligned. The connectors are respectively mounted on a first board and a second board and connect the first board and second board to each other.
The electrical connector for electrical connection to conductive pads on board members comprises a plug connector having first electrical contacts secure din a plug housing and including contact sections and termination sections for electrical connection to the conductive pads on one of the board members and a cap connector having second electrical contacts with a linear configuration secured in a cap housing and including contact sections electrically connecting with the contact sections of the plug connector when the plug connector and cap connector are mated together and termination sections for electrically connecting with the conductive pads of the other of the board members. The connector is characterized in that: each contact of the plug connector includes a base portion having a beam extending upwardly therefrom, the beam including a contact section thereon for mating with a corresponding linear contact of the cap connector. The beam further includes an S-shaped spring portion extending from the end thereof, the spring portion extending to an end portion that is substantially at the same height as the contact section on the upstanding beam. Upon mating the plug and cap connectors, the spring end portion presses against a central wall of the plug connector such that the S-shape contact sections of the plug connector are springably clamped between the linear contact sections of the cap connector and the wall of the plug housing.
As a result, even if the contacts are made smaller and shorter in order to reduce the pitch of the contacts, the first or plug contacts and second or cap contacts can be caused to wipingly contact each other with a high contact pressure. Furthermore, the first contacts are lined up in two rows so that the S-shaped spring members are mutually symmetrical in the opposing rows. As a result, the respective forces from the wall surfaces and the second contacts are balanced between the two rows, so that the first contacts and second contacts can be caused to contact each other with a high well-balanced contact pressure. Thus, an electrical connector that provides a secure electrical connection can be obtained.
Embodiments of the electrical connector of the present invention will now be described by way of example with reference to the accompanying drawings.